Chang et al. U.S. Pat. No. 4,788,420, entitled "System and Method for Reading Data Record Stripes on Data Cards," discloses one form of prior art point of sale terminal which incorporates a card reader assembly. The Chang et al. terminal utilizes a card guide which is integrally molded into the terminal case. A metal wear strip is molded into the bottom of the card guide slot to provide a surface which has better wear characteristics than the plastic material from which the terminal housing is formed in an injection molding process. In other prior art terminals, a separate metal wear strip is fastened to the terminal housing to form the bottom wall of a card guide slot to provide longer wear characteristics.
Kobayashi et al. U.S. Pat. No. 4,304,992, entitled "Magnetic Card Reader" discloses (FIGS. 4-6) a card reader in the form of a separate module with a housing that defines the card slot and encloses both the read head and decoder electronics for processing signals from the read head as a card is wiped through the slot. The card reader module is designed to be mounted to a point of sale terminal to provide a card reading function.
It is also known in the prior art to provide complete card reader subassemblies (i.e. with read head and decoder electronics together in a separate housing) that are designed to be physically integrated into the case of a point of sale terminal. For example, Tokin Corporation sells a card reader subassembly in which a read head frame snaps onto a card guide element. The read head frame carries a magstripe read head which is mounted in a separate bracket through which a thin pin-type spring extends. This spring can be carried in one or two possible pin mounting groove arrangements on the read head frame to position the read head at two different locations for alignment with different tracks on the magstripe card. While this card reader assembly has a fairly simple and low cost design, the use of a separate bracket and spring to carry the read head adds both parts and assembly labor cost to the overall unit.